This invention relates to an image forming apparatus that performs an image forming operation for forming an image on a recording medium.
Heretofore, a known image forming apparatus transfers a toner image formed on the surface of a photosensitive drum onto a sheet, using a transfer roller to which a transfer voltage is applied.
In such an image forming apparatus, the transfer voltage is applied to the transfer roller by either constant current control or constant voltage control. However, there is an image forming apparatus in which the type of application of the transfer voltage is switched between constant voltage control and constant current control, depending on a resistance value of the transfer roller, as disclosed in Unexamined Japanese Patent Publication No. 2000-2218 10, for example.